Will a Leak Reveal Trump’s Tax Returns? Don’t Hold Your Breath

WASHINGTON — The early days of the Trump administration have turned Washington into a land of leaks, with a national security adviser’s telephone calls, raw intelligence dossiers and confidential C.I.A. surveillance schemes spilling into the public. But the holy grail of leaks remains elusive: President Trump’s tax returns.

As taxpayers scramble to file their own returns and Republicans push to overhaul the tax code, attention has shifted back to Mr. Trump’s taxes and how he could benefit from the sweeping legislation he hopes to sign. Looking for the ultimate leak, opponents of Mr. Trump have wondered aloud how it could be that top intelligence agencies are suddenly fonts of classified information while the staid tax collector remains hermetically sealed.

“The American people deserve to know what conflicts of interest are hiding in Trump’s taxes,” said Delvone Michael, a member of the Tax March executive committee, which is organizing a mass demonstration to call for the release of the tax returns next month. “Every president in a generation has released his taxes. Trump must too.”

Mr. Trump broke with 40 years of tradition as a presidential candidate, declining to make his tax information public on the grounds that he was undergoing an I.R.S. audit. The government has made clear that is, in fact, no impediment to release, but since corporations like the Trump Organization are audited constantly, the excuse will not disappear, and he is not expected ever to release his returns willingly.

So how might Mr. Trump’s returns come to light?

If you’re thinking about a rogue I.R.S. agent or Russian cybertheft, don’t count on it.

It wouldn’t be easy. In 1973, an I.R.S. employee leaked private information from former President Richard M. Nixon’s taxes, resulting in a scandal that compelled him to declare, “I am not a crook.” Since then, the agency has taken rigid precautions to keep its data secure. Unauthorized disclosures come with steep penalties, including a prison sentence of up to five years and a $5,000 fine.

“I think an I.R.S. leak is extremely unlikely,” said Fred Goldberg, who served as I.R.S. commissioner from 1989 to 1992. “It’s a combination of the culture, the legal framework, the logistics and the risks.”

Although the I.R.S. has nearly 80,000 employees, the agency uses strict safeguards when it comes to privacy. The number of people with access to returns is limited, and improper browsing of taxpayer files is automatically flagged.

Hard copies of presidential returns historically have been kept in a safe outside of the commissioner’s office, tax experts say. Returns of celebrities are protected even more carefully than those of regular taxpayers.

“I would never say never, because it has happened in the past,” said Lawrence B. Gibbs, another former I.R.S. commissioner who was its chief counsel when Mr. Nixon’s tax information was made public. “But people are probably going to have to look elsewhere than the I.R.S. for the president’s tax returns if that’s what they want.”

A breach of the I.R.S. is another possibility, and the release this week of a trove of C.I.A. data shows that even the most tightly guarded corners of the government are vulnerable. Thin resources are also a problem, but since a 2015 hack of I.R.S. data using false identities, the agency has been working to bolster its defenses.

Jeffrey Greene, senior director for global government affairs and policy at the cybersecurity firm Symantec, said that the agency appears to have strengthened its computer systems since the theft two years ago, noting that Mr. Trump’s returns remained secure during the presidential campaign.

“Just the simple fact that those returns were never stolen or leaked over the past year speaks to the level of security on them,” said Mr. Greene, whose company works with the I.R.S.

Democratic lawmakers lately have been playing the national security card, clinging to the notion that congressional investigations into Mr. Trump’s ties with Russia will be the key. Twice this month they have forced votes to demand the returns’ release, but Republicans have closed ranks around the president.

“Fully investigating Trump associates’ ties to Russia must include allowing both Democrats and Republicans on the Finance Committee to privately review Mr. Trump’s returns,” Senator Ron Wyden of Oregon, the ranking Democrat on the committee, said earlier this week before his proposal was swiftly rejected by Republicans.

The next best hope is the coming wave of “emoluments” lawsuits that allege Mr. Trump is in violation of the Constitution because his business operations accept payments from foreign governments. A lawsuit that was filed in January by the liberal watchdog group Citizens for Responsibility and Ethics in Washington seeks to stop Mr. Trump’s businesses from accepting such payments. If the case moves forward, Mr. Trump’s tax returns could be extracted in the discovery process.

“I think that certainly in our emoluments case they will be germane to establish the foreign cash and relationships and other benefits,” said Norman L. Eisen, an Obama administration ethics lawyer who is on the legal team that filed the lawsuit. “Should we make it to discovery, we’ll seek them.”

If the court system seems too cumbersome, there are potential targets beyond the I.R.S. Mr. Trump’s lawyers and accountants who keep copies of his returns could also be vulnerable to hacking. And the White House and Trump Tower, where copies of Mr. Trump’s files could potentially be stored, have also proved susceptible to leaks.

Thus far, the most significant window into Mr. Trump’s taxes came from a portion of his 1995 returns that was sent anonymously to the The New York Times last October. That showed that he could have used tax loopholes to avoid paying federal income taxes for up to 18 years.

The Trump administration’s rush to rewrite the tax code by August will probably amplify the cry for more information about Mr. Trump’s taxes. Whatever plan he decides to ultimately support will raise new questions about how he might benefit from an array of new incentives.

“There are a number of tax proposals that would benefit him on a personal level,” said David Herzig, a tax expert at Valparaiso University School of Law, who pointed to a potential estate tax repeal and lower individual tax rates for the rich. “There are many dimensions to tax reform, but the constant is that the proposed modifications help people that have similar investment profiles as President Trump.”

A version of this article appears in print on , on Page A18 of the New York edition with the headline: Will I.R.S. Leak Reveal the President’s Tax Returns? Don’t Hold Your Breath. Order Reprints | Today’s Paper | Subscribe